The overall aim of this investigation is to improve our understanding of the proliferative abnormalities in hematopoietic tumors in order to develop more effective treatment. We are conducting a comprehensive survey of key proliferative parameters of the neoplastic cells in all types of hematopoietic tumors and correlating these measurements with cell marker studies and selected clinical features such as morphologic type, stage of disease, rate of clinical progression, responsiveness to treatment, remission duration and survival. In some tumors such as acute leukemia and chronic myelogenous leukemia, it is possible to obtain repeated marrow samples during treatment and to make quantitative measurements of the extent of kill of tumor cells and of repopulating normal hematopoietic cells during remission. Studies are also being conducted on human leukemic and lymphoma cells in short-term culture systems to determine their potentials for proliferation and differentiation in vitro, and to study their interactions with other cells and the influences of natural and artificial regulatory factors. Established cell lines originating from normal and neoplastic hematopoietic cells with well-calibrated cytokinetic parameters are also being used to determine the perturbations caused by selected drugs, drug combinations and natural factors, also with the goal of developing improved treatment regimens. A related objective is to purify and characterize normal hematopoietic progenitor cells from the marrow and blood of normal subjects and from patients following chemotherapy. Serial quantitative measurements are being made of normal hematopoietic precursors during recovery from treatment in order to serially determine the absolute number of progenitors in the marrow and blood and the proper timing necessary to collect and preserve these cells for subsequent autologous tem cell transplantation. For samples contaminated with tumor cells, experiments have been initiated to purge them of residual tumor cells, using either monoclonal antibodies or chemotherapeutic agents.